Gripping means for hydraulic ram type of metal shaping presses



May 18, 1.948. B. LERMQNT 2,441,707

GRIPPING MEANSFOR HYDRAULIC RAM TYPE OF METAL SHAPING PRESSES Y Fld Sept. lO, 1945 2 Sheets-Sheet 1 FIGLI.

2@ j" sa B. LERMONT l May 18, 1948. 2,441,707.

GRIPPING MEANS FOR HYDRAULIC RAM TYPE oF METAL SHAPING PRESSES Filed sept. 1o, 1943 2 sheets-sheet 2 FIC-3.4.

JNVENToR. BAS/L sfPMa/vr @ATTORNEYS Flcsfs,

*W'MEWM Patented May 18, 948

GRIPPING MEANS. FOR HYDRAULIC ItAM TYPE OF METAL SHAPING PRESSES Basil Lermont, New York, N. Y., assigner, by mesne assignments, to Sutton Patents, Inc., New York, N. Y., a corporation of New YorkA l Application September 10, 1943, Serial No. 501,774

This invention relates to improvements in devices for shaping sheets of metal into curved or concavo-convex form and relates particularly to improvements in devices of the type disclosed in my co-pending applicationl Serial No. 493,984, led July 9, 1943 and subsequently abandoned.

'Ihe aforementioned co-pending application discloses a-device for shaping sheets of metal which includes a ram mechanism having a form or die supported thereby which can be brought into engagement with a sheet of metal and pressed against the metal in order to deform the metal into a shape substantially complemental to the shape of the form.

In order to retain the sheet under tension during shaping of the sheet, 'the end and the side edge portions of the sheet are gripped by suitable gripping members and the movement and location of the gripping elements are regulated so that al controlled ilow of the metal in the sheet is obtained. By arranging the gripping members in the manner described above, it is possible to reduce to a large extent the tendency of the metal to ow inwardly from the edges and thereby prevent the sheet from becoming narrower and wrinkling.

It hasbeen found, however, that in some types of operations there is a tendency of the ksheet to flow more at one zone ythan at another forthe reason that one portion ofthe sheet may be stretched to a greater extent than another portion. Sometimes wrinkles are formedin the portion of a sheet in Whichthe greatest flow of metal takes place vand in some instances the sheet tears for the reason that the clamping or gripping means engage the edges of the sheet rigidly and cannot move with the sheet to equalize thestresses exerted parallel to the gripping means.

An object of the present invention is to provide gripping means for gripping the edges of the sheet which are capable of slight movement relatively to the form so as to compensate for flow of metal Vparallel tothe edges' of the sheet.

Another object of the invention is to provide a ram type 'of device having gripping jaws which are mounted for universal movement so that they can move endwise with the sheet, while at the same time exerting a transverse'stretching action on the sheet thereby to compensate for the flow of the metal.

Other objects of the invention will become apparent from the following description of a typical form of device embodying the invention.

In accordance' with the present invention, a

4 Claims. (Cl. 153-48) device is provided that includes a ram for shaping sheets of metal and members for gripping and retaining the ends and edges of a metal sheet. Some of the gripping members are mounted with capacity for movement in substantially all directions to subject lthe sheet to controlled tension, but permitting a certain freedom of movement of the retained edges of the sheet to compensate for stresses exerted at angles to the directions in which the sheet is tensioned.

More particularly, the members for gripping the lateral edges of the sheet are supported for universal movement on a mechanism for moving the gripping members to exert tension on thel sheet, and the mechanism is mounted for universal movement, likewise, whereby the gripping members can move toward and away from the ram, and in the direction of the length of the gripping members without binding during any of these movements.

The freedom of movement of the gripping members allows the gripped portion of the sheet to shift slightly in response to stresses thereon with thev result that the stresses on the sheet. are equalized and more uniform ow of the metal in the sheet results during the forming operation.

For a better understanding of the present invention, reference may be had to the accompanying drawing, in which:

Figure 1 is a plan view of a typical form of v device embodying the present invention;

Figure 2 is a view in cross-section taken on line 2 2 of Figure 1;

Figure 3 is a view in perspective of a typical form of gripping mechanism embodying the present invention;

Figure 4 is a view in longitudinal section vof the gripping jaws disclosing the actuating mechanism for the jaws;

Figure 5 is a view in transverse cross-section of the gripping jaws shown in open position; and

Figure 6 is a view in transverse cross-section showing the jaws in closed position.

The device chosen for illustrating the invention consists of a frame I0 including a pair of spaced apart, parallel side members Il and I2 which are connected by transversely extending members |13. Between the side members Il and l2 and disposed substantially centrally with respect thereto is a hydraulic ram I4 carrying a platen I5k at its upper end which is provided with a form I6. The form I6 may` be of substantially any desired shape depending upon the curvature that is to be imparted to the metal afiiigov sheet S. As illustrated, the form I 6 is of generally rectangular shape and is curved longitudinally and transversely. It will be understood that the form IB may .be varied widely in shape depending upon requirements and is not limited to the shape illustrated.

At opposite ends of the frame Hl are disposed hydraulic .cylinders l1 havingl piston rods I8 therein which are joined to gripping members J of a type disclosed more particularly in my copending application Serial No. 493,984, led July 9, 1943 and subsequently abandoned. Themembers J consist of a pair of pivotally connected jaw elements I9 and 2G havingoomplementally curved edges for engaging the .ends of the sheet S. The jaw elements I9 and 20 arel joined lby a hinge connection 2li which permits them to he opened and closed, preferably by means of hydraulic rams and toggles (not shown) A gripping member J of the type described above is provided at each end `of the `frame `II! and may be supported on the spaced apart. arms Via and ,isav that are connected Ato the oppsite ends of a shaft i-Sb which is rotatably fmburrlcd in the frame i3 so the member J may `,bcmoved pivotally about the axis of the shaft i811, to .exert a desired tension on the Vsheet S by means of the hydraulic motors, each including a cylinder H and ka piston rod I-8.

The device is also provided with lateral Vgri-pping members J of novel type which will -be `tieser-ibed now.

On opposite sides oi the frame lil and projecting outwardly from the side members Il and i2 are pairs of spaced yapart lugs 2'2 and 23, shown more particularly in Figure v3, between which is pivotally mounted a block24 by means of ashaft or spindle 25. The upper end of the block 24 is provided with a reduced portion 26 which is received in a bifurcated portion 2?! at .the lower end of the cylinder 28. The biiuroated portion 2? is joined to the block :24 rby means of a pivot pin 29 extending at right angles to the `spindle 25, thereby providing a universal connection and permitting rocking movement of the cylinder 28 about axes at `right angles.

r-Ihe cylinder 28 is provided with va piston (not shown) having a piston rod :26a `connectedthereto which projects from the upper end vof the cylinder and is provided with agblock 30 on the end thereof which is received in the bifurcated bracket 31. The bracket 3| and the `block 30 `are joined by means of a pivot pin 32 extending parallel with the pi-vot -pin 2,9.

AThe bifurcated bracket 3| is .pIDVded with an aperture 3io through which passes a hinge pin 33 that supports for pivotal movement a pair of gripping jaws 34 and 35. 'Each QI the jaws 34 and 35 is provided with lugs 340i` -and'3 5.1, respectively, `having apertures Atherein for receiving the hinge pin 33 and permitting them to oscillate about the hinge pin 3.3. It should b e noted that the hingepin 33 extends vSubstarltiillly parallel to the pivot pin 25 and thus While 'the cylinder may rock about .the 4pivots 291,.a11d 25, the jaws may oscillate about the .hinge pins33 and 32 and remain substantially parallelfto the pin 25.

The jaws 33 and 35 are opened and closed by the mechanism disclosed in Figures .4, .5 and .6. The jaws 34 and V35 are provided with ycircular apertures 34o and 35h in .which is receiveda rod" 3'6 extending entirely through `the jaws. Adjacent -the Aopposite ends of the rod 36 ,arepozftions 31 and 3.8 of reduced oval cross-section means, or the, eyiinoer 39 and piston 4o which is connected to the end of the rod 36. Thus, plfculieis supplied to the inlet 4| of the cylinder39f, the-piston 40 and rod 36 are urged to the right, .causing the jaws 34and 35 to close and lp .the ,sheet of metal S. When iiuid is supplied to the connection 42, the piston 40 and the rodV 35 are shifted to the left to release the jaws as shown in Figure; 5.

rihe gripping members .J are. maintained in upright position and are prevented trom fall?. ing inwardly or outwardly by means. 4QI the. extensible rods .33. The rods 4.3 are pivotally connected to .the lfran-1e member il or l2 and the block 30 at. the .upper ,end of the piston rod 29,. The rods, 43 may be provdedmith turnbuckles id permitting the. rods to. be lengthened ,or shortened. The. rods .4.32ct .as thrust Vinernbers to. permit the sheet S to `be A.tensioned transversely, but .d0 not prevent slight cndwseshfingof the. jaws 34 and35 to .compensate for shitting of, the. sheet S lengthwise. Y

in operation, the members .J `elfe @Situated to grip a sheet of metal and pressure is. exerted in the :hydraulic cylinders I 1. to ,move .the members J outwardly to .place the sheet .S .under .endwe tension. The side gripping members .J may likewise be closed upon the lateral `edges ,of .the sheet S .and `by supplying, fluid .pressure to the cylinder 28, the Sheet ofV metal iS. subjected to transverse tension. When .the ram i 4 is Vactuated and `the form i6 is iorced against .the tensioned sheets, the sheet S iS stretched :beynd its elastic limit and .deformed permanently into a shane complemental to the surface of the form 4,6. During vthe shaping operation, L,tl.1.=. tensor1 .ofthe members `J .and J may be increased or .decreased as necessary.

When the sheet S vis stretched more .at one .end

than another, there may be a tendency ,for a portion .of the sheet to V.move Vslightly .endwise yin order to compensate f0.1" the unequal 110W 0f .the metalyI-nasriiucb as the `edge .gripping-members J' on opposite. sides of the form are .capable of rocking movement, they .can Yvary their position and travel slightly lwith the Ysheet in eridwise. direction .without losing their parallel relation.- ship or altering their argular relationship to .the edges of the sheet S. In this-way, ,there is .no tendency for the side gripping ,members :J to rock and thereby exert ,a `varying tensionV transversely of the sheet.. ,Moreoverthe pivotal support for .the members 5J always v'retraits :them to move intoaiignment with the sheet, thereby preventing bending ofthe sheet at the .edges` of :the gripping means .JZ regardless .of the position the edges .of the sheet 1S assume. Y Thus, tbeiateraisripoing members YJ permit the necessary slight vmovcrner.it.of` the sheet to prevent the formation of wrinlgles or tears the sheet.

it 1will be understood .that :narices of Vthe ztybe described Therein .can he -modiilcd .@Qifisiderably without departing from the invention.

the size and shape of the form, the location and size of the gripping elements, the type of mechanism for actuating the members and the type of universal mounting for the members J may be varied considerably without departing from the invention, Moreovengripping members like the members J may be substituted for the members J and the number of these elements may be varied as desired. 1

Therefore, the form of the invention described herein should be regarded as illustrative and not as limiting except as required by the scope of the claims.

I claim:

1. In a gripping and tensioning member for a metal-forming device having a frame and a metal-shaping form; the combination of a cylinder, a piston in said cylinder, a piston rod connected to`said piston, an universal connection between one end of saidcylinder and said frame, a pair of pivotally connected jaws mounted on said piston rod for substantially universal movement relatively thereto, and means for supplying fluid pressure to said cylinder to extend and retract said piston rod.

2. A gripping and tensioning member for a metal-forming device having a support, comprising a hydraulic ram having a cylinder, a piston and a piston rod, means connecting said cylinder to said support for universal movementv relatively thereto, a member pivotally connected to one end of said piston rod, a hinge pin passing through said member at a right angle to the axis of the pivotal connection between said member and said piston rod, a pair of elongated gripping jaws hingedly connected by said hinge pin, and means carried by said jaws for opening and closing said ing apertures in said jaws adapted to be aligned when said jaws are together, a piston having a piston rod projecting 'from said cylinder, and having portions fitting said apertures, and, means forming zones of reduced cross-section in said rod receivable in said apertures to permit said jaws to separate.

f 4. A gripping and tensioning member for a metal-forming device having a support, comprisying a hydraulic ram having a cylinder, a piston and a piston rod, means connecting said cylinder to said support for universal movement relatively thereto, an adjustable thrustmember pivotally connected to said piston rod and said support and forming therewith a triangulated structure for supporting said cylinder in a predetermined relation to said support7 a member pivotally connected to one end of said piston rod, a hinge pin passing through said member at a right angle to the axis of the pivotal connectionbetween said member and said piston rod, a pair of elongated gripping jaws hingedly connectedby said hinge pin, a cylinder carried by one of said jaws, means forming apertures in said jaws r*adapted to be aligned when said jaws are together, a piston having a piston rod projecting from said cylinder and having portions fitting said apertures, and means forming zones of reduced cross-section in said rod receivable in said apertures to permit said jaws to separate.

BASIL LERMONT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 519,086 Larson May 1, 1894 646,936 Algeo, Jr. Apr. 10, 1900 1,315,937 Artz Sept. 16, 1919 2,006,468 Longren July 2, 1935 21,129,774 Kuhner Sept. 13, 1938 FOREIGN PATENTS Number Country Date 21,434 Germany May 8, 1883 506,780 Great Britain June 5, 1939 

